Update: Following the Android 8.0 firmware update for the Xiaomi Mi 6, Mi Mix 2, Redmi Note 4, etc, the manufacturer has now released official Global MIUI 9.5.6.0 ROM based on Android 8.1 Oreo. Some ROMS also support the latest Project Treble. Although Xiaomi is way behind other leading manufacturers in terms of the Android updates, the manufacturer is now stepping forward with Android 8.1 OS upgrade. Xiaomi is trying hard to bring about the latest Oreo updates for several devices along with the Project Treble support. So download and install the latest MIUI 9.5 for Xiaomi Mi A1, Mi 6, Mi Mix 2, and several other smartphones.

The first MIUI 9 Oreo Global Beta ROM is now available for download starting the Mi 6 and the Mi Mix 2. It comes with build number 8.1.11 based on the Android 8.0. The MIUI 9 8.1.11 comes to most of the Xiaomi devices. However, only the Mi 6 and Mi Mix 2 receive Oreo at this moment. Other devices are still stuck on Android 7.0/7.1 Nougat.

It is a beta update, you can download MIUI 9.5.3 ROM from above > rename the file to update.zip > place the update.zip in internal storage > open the updater app > chose update package > and select the downloaded file.